This invention relates to a coin sensor device and more particularly to a coin sensor device and method for use with a coin-operated vending system for detecting undesired and counterfeit coins, slugs, and non-coin objects deposited or inserted into such systems and for distinguishing acceptable coins therefrom, and for determining or assisting in determinations of the denominations of the acceptable coins.
Coin-operated devices and systems of many types and variations are widely employed. For proper operation of such coin-operated devices and systems verifications means must be used to distinguish between acceptable and unacceptable coins and for discriminating between various denominations of acceptable coins. In many coin-operated devices in use today, coin acceptor means are provided for checking the dimensions of a deposited coin to determine whether or not such coin is of a proper size to be an acceptable coin. Most devices that perform such coin sizing checks make use of electrical or electronic means for determining or measuring coin dimensions. In order to check the dimensions of a deposited coin such means as a debouncer are used to settle or stabilize the coin as it passes by sensors. If the coin is not debounced it moves erratically by the sensors causing errors in discriminating between acceptable and unacceptable coins.
In the prior art there are many devices in existence that include sensors located to respond to movements of objects including coins. Some of the known devices measure or discriminate between objects or coins based on differences such as differences in coin size or diameter, and some employ sensors located at more than one elevation above the track or rail that the objects or coins move on, such for example, as the device disclosed in Kai et al U.S. Pat. No. 5,033,603. Other devices or sensors include means to illuminate coins or portions thereof as they move along the coin path usually by light sources oriented perpendicularly to the coin path. Such devices may employ photosensitive devices which convert changes in the light signals into electrical signals representative of some coin characteristic such as coin diameter. Typical of such devices is that disclosed in Saarinen et al U.S. Pat. No. 5,033,602.
Another coin sensing device is disclosed in Fougere U.S. Pat. No. 3,797,628 which discloses a coin selector which includes velocity determining means that operate on a chordal dimension of the coin. The device includes circuit means that compare resultant detected information with predetermined stored information that has characteristics that are considered to be representative of acceptable coins.
Another patent of interest is Johnston U.S. Pat. No. 3,797,307 which discloses a coin discriminator device which performs several different tests on each coin that passes and establishes values dependent on at least one of the tests.
Other patents of interest are Roberts et al U.S. Pat. No. 4,447,281 which discloses an apparatus for coin diameter computation and Chow et al U.S. Pat. No. 4,509,633 which discloses an electronic coin validator that includes diameter sensing means.
The present invention is distinguishable from the devices disclosed in the cited prior art by using two spaced sensors both located at or near the same predetermined height or distance above the track or rail along which coins travel on edge so that all coins moving along the track will be able to interrupt both sensors but for somewhat different time periods depending on the coin type or other characteristic such as coin diameter. In the present device both sensors will be interrupted in sequence by the leading edge of every coin, and both will reestablish the interrupted energy beam to the respective sensor across the feed path when the trailing coin edge moves past that sensor. The spacing of the sensors is important and is selected so that certain larger diameter coins, such as quarters, will be able to simultaneously effect or interrupt the beams of both sensors while smaller diameter coins, such as dimes, will be able to effect or interrupt only one sensor at a time. The time it takes for the leading edge of a coin to sequentially interrupt the beams of both sensors in sequence is an important time interval and depends on the speed of movement of the coin along the track. This time difference is used by circuit means such as by a microprocessor to make other determinations. The time when the trailing edge of a coin reestablishes the first beams is especially important because by that time any coin bounce that may occur when a coin lands on or falls on the track will have dissipated.
The present invention is for less affected by changes of the coins velocity during chordal and speed measurements since they predominately occur simultaneously, thereby achieving greater accuracy regardless of said changes.
The present construction provides a better, more accurate and relatively inexpensive coin sensing device, and one which provides an accurate way of identifying coins based by coin diameter. All this is made possible in a construction that has relatively few parts.